Yealink SIP-T21 E2 User Manual page 163

The MWI subscription parameters you need to know:
Options
Subscribe for MWI
MWI Subscription Period
Subscribe MWI To Voice
Mail
Note
The phone will send SUBSCRIBE messages for the MWI service to the account or the
voice number MWI service depending on the server. Contact your system administrator
for more information.
To configure subscribe for MWI via web user interface:
1. Click on Account->Advanced.
2. Select the desired account from the pull-down list of Account.
3. Select Enabled from the pull-down list of Subscribe for MWI field.
4. Enter the period time in the MWI Subscription Period(Seconds) field.
5. Click Confirm to accept the change.
Enable or disable a subscription for MWI service.
Period of MWI subscription. The IP phone sends a
refresh SUBSCRIBE request before initial SUBSCRIBE
expiration.
Enable or disable a subscription to the voice mail
number for MWI service.
To use this feature, you should also configure the voice
mail number.
Advanced Phone Features
Description
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